Submissions for variant NM_000038.6(APC):c.3675del (p.Lys1226fs)

Total submissions: 1

Submitter	RCV	SCV	Clinical significance	Condition	Last evaluated	Review status	Method	Comment
Labcorp Genetics (formerly Invitae), Labcorp	RCV004565563	SCV004325576	pathogenic	Familial adenomatous polyposis 1	2023-09-21	criteria provided, single submitter	clinical testing	This variant is expected to disrupt the EB1 and HDLG binding sites, which mediate interactions with the cytoskeleton (PMID: 15311282, 17293347). While functional studies have not been performed to directly test the effect on APC protein function, this suggests that disruption of the C-terminal portion of the protein is functionally important. For these reasons, this variant has been classified as Pathogenic. A different truncation (p.Tyr2645Lysfs*14) that lies downstream of this variant has been determined to be pathogenic (PMID: 9824584, 1316610, 27081525, 8381579, 22135120, Invitae). This suggests that deletion of this region of the APC protein is causative of disease. This variant has not been reported in the literature in individuals affected with APC-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change creates a premature translational stop signal (p.Lys1226Argfs*39) in the APC gene. While this is not anticipated to result in nonsense mediated decay, it is expected to disrupt the last 1618 amino acid(s) of the APC protein.